An artificial valve prosthesis

Abstract

The present invention discloses an artificial valve prosthesis, comprising a stent body and a leaflet assembly. The stent body includes a first stent and a second stent. The first stent has a connection end. Wherein, the second stent includes a plurality of stent rods, and the plurality of stent rods are respectively fixed to the connection end of the first stent. The leaflet assembly has a first leaflet fixing portion, and the leaflet assembly is fixed to the connection end of the first stent through the first leaflet fixing portion. Compared with the prior art framework structure composed of a plurality of closed geometric units, the second stent of the present invention is mainly composed of a plurality of stent rods, reducing the material of the stent body of the present invention, thereby reducing the cross-sectional area of the delivery device, and thus reducing the trauma area of the patient; in addition, the stent structure in the area sandwiched between the leaflet assembly and the second stent is relatively sparse, and blood is not easily deposited there, thus reducing the risk of thrombus formation.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a transcatheter artificial heart valve prosthesis. Background Art

[0002] The heart contains four chambers, the right atrium (RA), the right ventricle (RV), the left atrium (LA), and the left ventricle (LV). During the entire cardiac cycle, the pumping actions on the left and right sides of the heart generally occur synchronously. The valves that separate the atria from the ventricles are called atrioventricular valves, which act as one-way valves to ensure the normal flow of blood within the heart chambers. The atrioventricular valve between the left atrium and the left ventricle is the mitral valve, and the atrioventricular valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve directs blood flow into the pulmonary artery and from there to the lungs; the blood returns to the left atrium through the pulmonary veins. The aortic valve guides blood flow through the aorta and from there to the periphery. There is usually no direct connection between the ventricles or between the atria.

[0003] At the start of ventricular filling (diastole), the aortic valve and the pulmonary valve close to prevent backflow from the arteries into the ventricles. Shortly thereafter, the atrioventricular valves open to allow unobstructed flow from the atria into the corresponding ventricles. Shortly after the start of ventricular systole (i.e., ventricular emptying), the tricuspid valve and the mitral valve normally close, thereby forming a seal that prevents backflow from the ventricles into the corresponding atria.

[0004] When an atrioventricular valve has a problem and cannot function properly, it results in improper closure. Atrioventricular valves are complex structures that typically include an annulus, leaflets, chordae tendineae, and supporting structures. Each atrium is connected to its valve through an atrial vestibule. The mitral valve has two leaflets, and the similar structure of the tricuspid valve has three leaflets, and the attachment or engagement of the corresponding surfaces of each leaflet with each other helps to provide closure or sealing of the valve, thereby preventing blood from flowing in the wrong direction. Failure of the leaflets to seal during ventricular systole is called incomplete coaptation, which can allow blood to flow backward (regurgitate) through the valve. Valvular insufficiency of the heart can have serious consequences for the patient, often leading to heart failure, reduced blood flow, decreased blood pressure, and / or reduced oxygen flow to the body tissues. Mitral insufficiency can also cause blood to flow back from the left atrium into the pulmonary veins, resulting in congestion. Severe valvular insufficiency, if left untreated, can lead to permanent disability or death.

[0005] Left ventricular outflow tract obstruction is mainly caused by patients with hypertrophic cardiomyopathy, in whom the interventricular septum thickens and shows asymmetric thickening and hypertrophy, resulting in a narrowed outflow path when the left ventricle ejects blood. When the heart contracts, blood passes through the narrow area. Because the force at the narrow area is very large, the native valve leaflets are displaced or repaired and pushed to both sides, so this force will attract the native mitral valve to the interventricular septum, making the stenosis more severe. And in the late stage of cardiac contraction, the native valve leaflets can completely block the blood outflow path, forming left ventricular outflow tract obstruction. The common symptoms of left ventricular outflow tract obstruction are palpitations, shortness of breath, fatigue after activities, and even angina pectoris, syncope, accompanied by angina attacks, and heart failure may occur in the late stage.

[0006] A thrombus is a small mass formed on the surface of the exfoliation or repair site of the blood vessel inner surface in the cardiovascular system. In a variable fluid-dependent type, a thrombus is composed of insoluble fibrin, deposited platelets, accumulated white blood cells, and trapped red blood cells. When the intima is damaged, the endothelial cells degenerate, necrose and shed, and the subendothelial collagen fibers are exposed, thus activating factor Ⅻ of the intrinsic coagulation system. The intrinsic coagulation system is activated, and the damaged intima can release tissue thromboplastin to activate the extrinsic coagulation system. The damaged intima becomes rough, making it easy for platelets to aggregate, mainly adhering to the exposed collagen fibers.

[0007] In recent years, there have been some breakthroughs in the field of artificial valves. However, due to the complexity of the mitral valve and its surrounding structures, the treatment of the mitral valve still faces huge challenges. For example, 1. How to solve the deposition of blood flow at the connection position between the valve leaflets and the stent and avoid thrombus formation at this place; 2. How to reduce the diameter of the delivery valve device, thereby reducing the trauma area during implantation; 3. How to avoid the native valve leaflets blocking the outflow tract and solve the problem of outflow tract obstruction. Summary of the Invention

[0008] The present invention provides an artificial valve prosthesis that can solve the above-mentioned defects in the prior art.

[0009] The technical solution of the present invention is as follows:

[0010] An artificial valve prosthesis includes a stent main body and a valve leaflet assembly.

[0011] The stent main body includes a first stent and a second stent configured to have a grid-like frame structure. The first stent has a connection end. Among them, the second stent includes a plurality of stent rods, and the plurality of stent rods are respectively fixed to the connection end of the first stent. The valve leaflet assembly is configured with a first valve leaflet fixing portion, and the first valve leaflet fixing portion is fixed to the connection end of the first stent.

[0012] Compared with the prior art in which the stent body is a frame structure composed of several closed geometric units, the first stent of the present invention is a grid-like frame structure to ensure that the stent body can be compressed into the delivery device. The second stent is mainly composed of several stent rods, reducing the material of the stent body of the present invention, thereby reducing the cross-sectional area of the delivery device and the trauma area of the patient. Moreover, on the side away from the first stent in the area clamped by the leaflet assembly and the second stent, the stent structure at this place is relatively sparse, and blood is not likely to deposit here, thus reducing the risk of thrombus formation. In addition, when the second stent is anchored in the ventricle, the sparse stent structure is also beneficial to reducing the risk of outflow tract obstruction or stenosis.

[0013] In some embodiments, the first leaflet fixing part is configured to have an extended arc matching the connection end, so that the first leaflet fixing part coincides with the connection end. At this time, the area clamped by the leaflet assembly and the stent body and away from the first stent is completely a sparse structure formed by the stent rods, which can prevent blood from depositing in this area.

[0014] In some embodiments, the stent rods are fixed to the end(s) (one end or two ends) of the connection end, or the stent rods are arranged in a manner of being disposed between two adjacent leaflets. Preferably, when the leaflet assembly is configured with multiple leaflets, the joint between two adjacent leaflets is configured as the second leaflet fixing part, and the leaflet assembly is further fixed to the stent rods through the second leaflet fixing part. Such a structure enables the stent rods to provide a fixed position for the leaflets and corresponding acting forces for the opening and closing of the leaflets. Two adjacent leaflets are fixed to the stent rods through the second leaflet fixing part at the joint, reducing the opening amplitude of the leaflets and the acting force when the leaflets flap against the tissue when opening, thereby increasing the service life of the leaflets.

[0015] Furthermore, the number of stent rods is at least 2, preferably 2 - 5. If the number of stent rods is too large, it will increase the material of the stent body and the cross-sectional area of the delivery device, thereby increasing the trauma area. If the number of stent rods is too small, it cannot provide sufficient fixing force for the leaflets to ensure the smooth opening and closing of the leaflets.

[0016] In some embodiments, the stent rod is configured to have a first end for fixing to the first stent, and the stent rod also has a leaflet attachment part for fixing the leaflets. The distance between the end face of the leaflet attachment part and the first end accounts for 1 / 12 - 1 / 2 of the length of the stent rod. Since the area of the first stent is relatively large, the leaflets are sutured to the second stent rod close to the first stent, which is beneficial for the first stent to share the acting force of the leaflets on the stent rod and increase the durability of the stent rod.

[0017] Preferably, the first end portion is configured to be columnar or horn-shaped. When the first end portion is configured to be horn-shaped, it can make the stent rod and the first stent have a smooth transition, and can evenly disperse the force received by the stent rod on the entire first stent, increasing the durability of the stent body. Further, the leaflet attachment portion is configured with a plurality of suture holes, preferably circular holes, and the number of suture holes is 1-10, preferably 2-5.

[0018] In some embodiments, the free end of at least one of the stent rods is configured as a hook portion for hooking the native leaflet. The hook portion fixes the native leaflet to prevent the native leaflet from blocking the outflow tract, and can also be used to hook tissues, playing a certain anchoring role. Preferably, at least two of the stent rods in the second stent are configured with the hook portions, and among them, the hook portions should be symmetrically arranged, which can more effectively fix the native leaflet and at the same time make the anchoring of the stent body more stable.

[0019] In some embodiments, the angle γ formed by the second stent and the first stent is 10-175°, preferably, γ is 90-160°. At this angle, the first stent can be closely combined with the atrium, and the atrium can provide sufficient anchoring sites for the stent.

[0020] In some embodiments, the second stent further includes a leaflet cutting member for cutting the native leaflet. The leaflet cutting member cuts the native mitral valve and is hooked by the stent rods on both sides to prevent the native leaflet from blocking the outflow tract.

[0021] Preferably, the leaflet cutting member is fixed to the connection end of the first stent and is located between two adjacent stent rods, so that the native leaflet can be fixed by the hook portions of the stent rods on both sides after being cut.

[0022] In some embodiments, the leaflet cutting member is configured to extend in a direction away from the leaflet assembly, and the angle α between the leaflet cutting member and the extending direction of the stent rod is 0-90°. Further preferably, the angle α is 0-45°. This design can ensure that the native leaflet has been cut by the leaflet cutting member before the stent rod hooks the native leaflet, which can prevent the overly large native leaflet from blocking the outflow tract. At the same time, this angle can ensure that the leaflet cutting member does not interfere with the normal opening and closing of the replacement leaflet.

[0023] In some embodiments, the leaflet cutting member is configured with a plurality of cutting portions, and the cutting portions are triangular, square, or the cutting portions have arc-shaped cutting edges.

[0024] The cutting portions are arranged from the free end of the leaflet cutting member to the other end portion thereof. Preferably, along the extending direction of the leaflet cutting member, a plurality of the cutting portions are arranged continuously, or a plurality of the cutting portions are arranged discontinuously.

[0025] In some embodiments, the artificial valve prosthesis is used to replace a diseased native leaflet, such as replacing the anterior or posterior leaflet of the mitral valve, or repairing the tricuspid valve or aortic valve. In this case, the stent body is configured as a non-closed structure. When the valve prosthesis is used to replace the native valve, the stent body is configured as a circumferentially closed annular structure.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] First, for the artificial valve prosthesis of the present invention, the second stent is mainly composed of several stent rods, and the leaflet assembly is fixed to the second stent. Compared with the prior art where the stent body is a frame structure composed of several closed geometric units, the arrangement of the stent rods in the present invention reduces the material of the stent body, thereby reducing the cross-sectional area of the delivery device and thus reducing the trauma area of the patient. In addition, on the side away from the first stent in the area sandwiched between the leaflet assembly and the second stent, blood is not easily deposited there, thus reducing the risk of thrombus formation. Moreover, when the second stent is anchored in the ventricle, the structure of the stent rods helps to reduce the obstruction or blockage of the outflow tract.

[0028] Second, for the artificial valve prosthesis of the present invention, the connecting end of the first stent is configured to have a curvature matching the fixed end of the leaflet. After the leaflet assembly is fixed, the connection between the first leaflet fixing part and the connecting end of the first stent completely coincides. On the side away from the first stent, the area sandwiched between the leaflet assembly and the second stent is completely a relatively sparse structure composed of stent rods, so that blood will not be deposited there, further reducing the risk of thrombus formation. At the same time, it further reduces the material of the stent body and the cross-sectional area of the delivery device.

[0029] Third, for the artificial valve prosthesis of the present invention, the free end of the stent rod is also configured with a hook part for hooking the native leaflet to form a retaining force on the native leaflet to prevent the native leaflet from blocking the outflow tract during heart contraction, and it can also be used to hook tissues to play a certain anchoring role. The second stent is also configured with a leaflet cutting piece, which can cut the native leaflet and be hooked by the stent rods on both sides to prevent the larger native leaflet from blocking the outflow tract.

[0030] Of course, it is not necessary for any product implementing the present invention to achieve all the above advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a schematic diagram of the overall structure of the valve prosthesis according to Embodiment 1 of the present invention, where Figure 1A is a schematic diagram of the structure of the stent body, Figure 1B is a schematic diagram of the structure of the leaflet assembly;

[0032] Figure 2 is a schematic diagram of the overall structure of the stent body in the prior art;

[0033] Figure 3 is a schematic diagram of the overall structure of the stent rod according to Embodiment 1 of the present invention;

[0034] Figure 4 is a schematic diagram of a partial structure of the stent body according to Embodiment 1 of the present invention;

[0035] Figure 5 is a schematic diagram of a partial structure of another stent body according to Embodiment 1 of the present invention;

[0036] Figures 6 (A, B, C, D) are respectively schematic diagrams of the leaflet cutting member according to Embodiment 1 of the present invention.

[0037] Reference numerals: first stent 110; leaflet assembly 130; second stent 120; stent rod 121; first leaflet fixing portion 134, second leaflet fixing portion 135; leaflets (131, 132, 133); connection end 210; first connection end 211; second connection end 212; third connection end 213; first end portion 120-1; leaflet attachment portion 120-2; hook portion 120-3; leaflet cutting member 140; cutting portion 141. Detailed Description of the Invention

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] As used in this specification, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification, the term "or" is generally used in the sense of including "and / or" unless the context clearly dictates otherwise.

[0041] The present invention will be further described below in conjunction with specific embodiments.

[0042] Embodiment 1

[0043] This embodiment provides an artificial valve prosthesis (also denoted as valve prosthesis), see Figure 1A - Figure 6D , the valve prosthesis includes a stent body and a leaflet assembly 130. Among them, the stent body can serve as a support structure for the leaflet assembly 130, and at the same time play an anchoring role in anchoring with tissues, and a role in connecting with a delivery device (such as lugs or fixing ears are provided at one end or both ends of the stent body), etc. The artificial valve prosthesis of this embodiment is a transcatheter delivery valve prosthesis, and the valve prosthesis is compressed into a delivery device for delivery during implantation, and is released and anchored after being delivered to the target position. Among them, the stent body is made of biocompatible materials such as nitinol or cobalt-chromium, and the leaflet assembly 130 includes at least one artificial leaflet. According to actual clinical needs, the corresponding number of artificial leaflets can be set, and the artificial leaflets can be biological tissues such as bovine pericardium, porcine pericardium, and equine pericardium.

[0044] See Figure 1A , the stent body includes a first stent 110 and a second stent 120 configured to have a grid-like frame structure. The first stent 110 has a connection end 210, and the first stent 110 is connected to the second stent 120 through the connection end 210. Among them, the second stent 120 includes a plurality of stent rods 121, and the stent rods 121 are respectively fixed to the connection end 210 of the first stent 110. The leaflet assembly 130 is configured with a first leaflet fixing portion 134, and the first leaflet fixing portion 134 is fixed to the connection end 210 of the first stent 110.

[0045] Among them, the first stent 110 is configured as a grid-like frame structure composed of a plurality of closed geometric units arranged. The closed geometric units include but are not limited to triangles, squares, pentagons, teardrop shapes, heart shapes, rhombuses, etc., and are preferably composed of rhombus units arranged, so that the first stent 110 can be compressed into a delivery catheter for delivery. After its release, the first stent 110 self-expands and returns to its original state. The stent rods 121 can be fixed at the vertices or on the sides of the rhombus units of the first stent 110, so that the entire stent body can be compressed and can self-expand.

[0046] In the prior art, the stent body as a whole is a frame structure composed of several closed geometric units arranged, see Figure 2 , which is a partial structural schematic diagram of the stent body in the prior art, including an upper flared opening, the upper part of the lower ventricle, the middle part of the lower ventricle, and the lower part of the lower ventricle. Among them, the upper flared opening is anchored in the atrium, the valve leaf is fixed in the middle part of the lower ventricle of the stent body, the lower part of the lower ventricle is located in the ventricle, and blood flows in from the upper flared opening and out from the lower part of the lower ventricle. After the valve leaf is fixed, a region will be clamped on one side close to the lower part of the lower ventricle at the connection between the frame structure and the valve leaf, and this region is prone to blood deposition and form thrombus.

[0047] To solve the problem of thrombus formation, the prior art usually performs anti-thrombosis treatment on the material in contact with blood to reduce the formation of thrombus, but there is still a risk of thrombus formation. At the same time, how to reduce the material of the valve prosthesis to reduce the diameter of the delivery device is also a major problem faced.

[0048] Different from the structure of the stent body in the prior art and the technical concept for solving thrombus formation, the stent body of this embodiment includes a first stent 110 and a second stent 120. Among them, the second stent 120 includes several stent rods 121 fixed to the connection end 210 of the first stent. The rod-shaped structure of the stent rods 121 makes the second stent 120 formed into a relatively sparse stent structure. Different from the grid-like frame structure of the middle part of the lower ventricle and the lower part of the lower ventricle in the prior art, the second stent 120 of this embodiment does not form an intersecting network in the direction perpendicular to the extension direction of the stent rods. On the side far from the first stent 110 at the connection between the valve leaf assembly 130 and the stent body, the relatively sparse structure of the second stent 120 makes it difficult for blood to deposit in this region, reducing the risk of thrombus formation in this region. At the same time, the structure of the second stent 120 also reduces the material of the stent body, thereby reducing the cross-sectional area of the delivery valve prosthesis, and thus reducing the trauma area of the patient.

[0049] Furthermore, when the first stent 110 is mainly anchored in the atrium and the second stent 120 is anchored in the ventricle, compared with the stent body of the prior art, the structure of the second stent 120 makes the valve prosthesis more sparse on the side close to the outflow tract. Therefore, when the valve prosthesis of this embodiment is used as a mitral valve, it can reduce the obstruction of the left ventricular outflow tract, and when used as an aortic valve, it can reduce the obstruction of the left ventricular outflow tract.

[0050] Since the first leaflet fixing part 134 for fixing of the leaflet assembly 130 has a certain curvature, in some embodiments, the connecting end 210 is configured to have an extending curvature matching the first leaflet fixing part 134, so that the first leaflet fixing part 134 and the connecting end 210 completely coincide. Such a structure makes the area at the connection between the leaflet assembly 130 and the stent body and away from the first stent 110 a sparse structure entirely formed by several stent rods, further reducing the risk of thrombus formation in this area.

[0051] In this embodiment, the number of the stent rods 121 is at least 2, preferably 2 - 5. If the number of the stent rods is too large, it will increase the material of the stent body and the cross-sectional area of the delivery device, thus increasing the trauma area. If the number of the stent rods is too small, it cannot provide sufficient fixing force for the leaflets to ensure the smooth opening and closing of the leaflets.

[0052] The stent rods 121 can be located at any position of the connecting end 210 of the first stent. In some embodiments, the valve prosthesis is used to replace a locally diseased native leaflet, and the stent body is configured as a non-closed structure, such as a fan-shaped structure. When repairing the anterior leaflet of the mitral valve, it can be used in cooperation with the native posterior leaflet; when repairing the posterior leaflet of the mitral valve, it can be used in cooperation with the native anterior leaflet. Of course, such a structure can also be used for aortic valve or tricuspid valve repair, and the stent body and the leaflet assembly 130 are set according to different repair objects.

[0053] Continue to refer to Figure 1A As shown in the figure, the connecting end 210 of the first stent has two ends (A and E) along its extending direction. At this time, the second stent 120 is at least provided with two such stent rods 121. The stent rods 121 are preferably fixed to the ends of the connecting end 210, which can be fixed to one of the ends of the connecting end 210, or fixed to both ends of the connecting end 210. Compared with other positions, the stent rods 121 fixed at the ends can form a relatively stable support for the leaflet assembly 130. In some embodiments, when the leaflet assembly 130 is configured with multiple leaflets, the stent rods 121 can also be arranged between two adjacent artificial leaflets to fix the two adjacent leaflets. Wherein, the joint between two adjacent leaflets is configured as the second leaflet fixing part 135, and the leaflet assembly 130 is further fixed to the above-mentioned stent rods 121 through the second leaflet fixing part 135.

[0054] See Figure 1B, the leaflet assembly 130 has three artificial leaflets, namely leaflet 131, leaflet 132 and leaflet 133. The edge of the leaflet assembly 130 is configured as the first leaflet fixing portion 134 described above. A second leaflet fixing portion 135 is respectively configured between leaflet 131 and leaflet 132 and between leaflet 132 and leaflet 133. The connecting end 210 of the first stent 110 has a first connecting end 211, a second connecting end 212 and a third connecting end 213. The first connecting end 211 and the third connecting end 213 are symmetrically arranged on both sides of the second connecting end 212. Among them, each connecting end is used for fixedly connecting with a leaflet, and each connecting end is configured to have an extending arc matching the fixing end of the leaflet fixed thereto. Among them, a stent rod 121 is respectively fixed at the end point A of the first connecting end 211 and the end point E of the third connecting end 213. At the same time, a stent rod 121 is respectively configured at the corresponding positions between the first connecting end 211 and the second connecting end 212 and between the second connecting end 212 and the third connecting end 213, so that the two end points of the connecting end 210 and between adjacent two leaflets are respectively configured with a stent rod 121. After the leaflet assembly 130 is fixed, the second leaflet fixing portion 135 is respectively fixed to a stent rod 121. The stent rod 121 can provide a fixing position for the leaflet, provide a corresponding acting force for the opening and closing of the leaflet, reduce the opening amplitude of the leaflet, and reduce the acting force of the leaflet flapping the tissue when the leaflet opens, thereby increasing the service life of the leaflet. At the same time, it can provide a stable supporting effect for the leaflet assembly 130 and prevent the leaflet from detaching from the stent rod when the leaflet closes.

[0055] The second stent 120 can provide a fixing position for the leaflet. Optionally, the fixing position can be located at any position of the stent rod 121. Specifically, see Figure 3 , in some embodiments, the stent rod 121 is configured to have a first end portion 120-1 for fixing with the first stent 110. The stent rod 121 also has a leaflet attachment portion 120-2 for fixing the leaflet. The distance between the end face of the leaflet attachment portion 120-2 and the first end portion 120-1 accounts for 1 / 12 to 1 / 2 of the length of the stent rod 121. Due to the large area of the first stent 110, the leaflet assembly 130 is sutured at a position slightly above the middle of the stent rod 121, which is beneficial for the first stent 110 to share the acting force of the leaflet assembly 130 on the stent rod 121.

[0056] Furthermore, the leaflet attachment portion 120-2 is configured to have a plurality of suture holes, which can be rhombic, circular, triangular, etc., preferably circular. The circular small holes can evenly disperse the force of the leaflet assembly 130 on the stent rod on the stent rod 121, thereby increasing the durability of the stent rod 121. The number of suture holes can be 1-10, preferably 2-5. The more the number of suture holes, the weaker the strength of the stent rod. The fewer the number of suture holes, the weaker the supporting force of the stent rod on the leaflet assembly 130 will be.

[0057] Furthermore, the first end portion 120-1 can be configured as a columnar shape, such as a cylindrical shape or a prismatic shape (such as a quadrangular prism). Preferably, the first end portion 120-1 can be configured as a flared shape, such as Figure 3 shown. The flared shape can make the stent rod 121 and the first stent 110 transition smoothly, and can evenly disperse the force received by the second stent 120 on the entire stent body, increasing the durability of the stent body.

[0058] In some embodiments, the shape of the free end of the stent rod 121 can be cylindrical or conical. Preferably, the free end of the stent rod 121 is configured as a hook portion 120-3 in the shape of a hook. The hook portion 120-3 at the free end of the stent rod 121 can hook the native leaflet or tissue, which can play a role in fixing the stent body. At the same time, the movement range of the native leaflet is restricted, further reducing the risk of the native leaflet blocking the outflow tract.

[0059] In some preferred embodiments, at least two of the stent rods 121 in the second stent 120 are configured with the hook portion 120-3. The more the number of the hook portions 120-3, the greater the acting force on the native leaflet, preventing the native leaflet from causing outflow tract obstruction during cardiac systole. More preferably, the stent rods 121 configured with the hook portion 120-3 should be symmetrically arranged on both sides of the midpoint C of the connection end 210 of the first stent. As shown in Figure 1, when the connecting rod 120 at the position of the connection end A of the first stent 110 has a hook portion, correspondingly, the connecting rod 120 at the position of E is also configured with a hook portion. The hook portions are symmetrically arranged, making it easier to balance the acting force of the native leaflet or tissue on the stent body, and the stent anchoring is more stable.

[0060] In some embodiments, the angle γ formed by the second stent 120 and the first stent 110 is 10-175°, preferably γ is 90-160°, such as Figure 4 shown. At this angle, the first stent 110 can be closely combined with the atrium, and the atrium can provide sufficient anchoring sites for the first stent 110.

[0061] In a preferred embodiment, the second stent 120 further includes a leaflet cutting member 140 for cutting the native leaflets. For example, when repairing the mitral valve, the larger native leaflets can be incised by the leaflet cutting member 140 to avoid the outflow tract being blocked by the over-sized native leaflets. See Figure 1A , Figure 5 . Further, the leaflet cutting member 140 is fixed to the connection end 210 of the first stent 110 and is fixed between two adjacent stent rods 121. The stent rods 121 on both sides of the leaflet cutting member 140 should be configured with the above-mentioned hook portions so that after the native leaflets are incised by the leaflet cutting member 140, the native leaflets can be hooked by the stent rods 121 on both sides.

[0062] Taking the side where the leaflet assembly 130 is located as the inner side of the stent body or the valve prosthesis, in some embodiments, the leaflet cutting member 140 is configured to extend in a direction away from the leaflet assembly 130. See Figure 4 , the leaflet cutting member 140 extends towards the outside of the stent body, and the angle α between the extending direction of the leaflet cutting member 140 and the stent rod 121 is 0 - 90°; further preferably, the angle α is 0 - 45°. This design can ensure that the native leaflets are incised by the leaflet cutting member 140 before the stent rods 121 hook the native leaflets, so that the native leaflets can be effectively fixed and prevent the over-sized leaflets from blocking the outflow tract. At the same time, this angle makes the leaflet cutting member 140 away from the leaflet assembly 130, which can ensure that the leaflet cutting member 140 does not interfere with the normal opening and closing of the replacement leaflets.

[0063] In some embodiments, the leaflet cutting member 140 is configured with a plurality of cutting portions 141. See Figure 6A - Figure 6D , the cutting portions 141 can be configured as triangles, squares, or the cutting portions 141 have arc-shaped cutting edges. The specific form of the cutting portions 141 can be set according to actual clinical needs. Specifically, in order to prevent the cutting portions 141 from damaging the delivery device or tissue, the cutting portions 141 can be configured as smooth structures. Further, in order to achieve a better cutting effect, the cutting portions 141 can be configured with sharp cutting structures, such as having sharp cutting tips or having blade-shaped cutting parts. At this time, the cutting portions 141 can also be selected to be made of degradable materials, such as polylactic acid, which can be degraded after cutting.

[0064] In some embodiments, along the extending direction of the leaflet cutting member 140, a plurality of the cutting portions 141 are arranged in a continuous manner. See Figure 6B and Figure 6C , the cutting portions 141 are adjacent to each other in sequence. The continuously arranged cutting portions can make the cutting smoother. In some embodiments, a plurality of the cutting portions 141 are arranged in a non - continuous manner. SeeFigure 6A and Figure 6D The cutting parts 141 are arranged at intervals. The discontinuously arranged cutting parts can provide greater cutting force.

[0065] Continuing to refer to FIG. 1, the leaflet cutting member 140 is fixed at the 1 / 12 - 11 / 12 position of the second connection end 212. Preferably, the leaflet cutting member 140 is fixed at the midpoint C of the second connection end 212. This position can evenly disperse the force of the leaflet cutting member 140 on the left and right sides of the first stent 110.

[0066] In a specific embodiment, the cutting part 141 can be configured to be received in the leaflet cutting member 140 in the implanted state. When in use, the cutting part 141 can be exposed by operating the set rotary handle to achieve cutting.

[0067] In some embodiments, the artificial valve is used for the overall replacement of the mitral valve, tricuspid valve or aortic valve. At this time, the stent body should be configured as an annular closed structure. That is, the first stent 110 is configured as a circumferential annular closed structure, the leaflet assembly 130 is fixed on the inner circumferential side of the annular stent body, and the stent rods 121 of the second stent 120 are arranged along the circumference of the first stent 110. At this time, the material of the stent body can also be a balloon-expandable material.

[0068] Specifically, the above-mentioned first stent 110 and second stent 120 are fixedly connected to each other. The connection methods include but are not limited to welding, clip fixing, sewing or one-piece preparation. Preferably, one-piece preparation can reduce the preparation process, enhance the connection strength, and provide active supporting force for the leaflets. The leaflet assembly 130 is fixedly connected to the second stent 120. The connection methods include but are not limited to welding, clip fixing or suturing. Preferably, suturing is used. Further, to increase the biocompatibility of the second stent 120, biocompatible materials such as PET and PTFE can be wrapped on its outer side.

[0069] For the valve prosthesis provided in this embodiment, due to the design of the stent rods in the second stent 120, it replaces the reticular frame structure in the middle and lower parts of the lower ventricle in the prior art, reducing the material of the stent body. And on one side of the connection between the leaflet assembly and the second stent, it is a sparse structure composed of stent rods. Therefore, blood is not easily deposited at this place, thereby reducing the risk of thrombus formation. At the same time, it also helps to reduce the outflow tract obstruction or blockage.

[0070] The above-disclosed are only the preferred embodiments of the present invention. The preferred embodiments do not elaborate on all details. It should be understood that these embodiments are only used to illustrate the present invention, rather than to limit the protection scope of the present invention. The present invention is only limited by the claims and their full scope and equivalents.

[0071] These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention. Obviously, according to the content of this specification, many modifications and variations can be made. In practical applications, the improvements and adjustments made by those skilled in the art based on the present invention still fall within the protection scope of the present invention. The technical features in the above different embodiments can be arbitrarily combined on the premise that they do not conflict with each other.

Claims

1. An artificial valve prosthesis, characterized in that, It includes a stent body and a leaflet assembly. The stent body includes a first stent and a second stent configured to have a mesh frame structure. The first stent has a connection end. Among them, the second stent includes a plurality of stent rods, and the plurality of stent rods are respectively fixed to the connection end of the first stent. The rod-shaped structure of the stent rods causes the second stent to be formed into a relatively sparse stent structure. The leaflet assembly is configured with a first leaflet fixing portion, and the first leaflet fixing portion is fixed to the connection end of the first stent; the second stent further includes a leaflet cutting member for cutting the native leaflet; the leaflet cutting member is configured to extend in a direction away from the leaflet assembly, and the included angle α between the leaflet cutting member and the extending direction of the stent rod is 0-90°.

2. The artificial valve prosthesis according to claim 1, characterized in that, The connection end of the first stent is configured to have a curvature matching that of the first leaflet fixing portion, so that the first leaflet fixing portion coincides with the connection end.

3. The artificial valve prosthesis according to claim 1, wherein, The stent rods are arranged at the end of the connection end, or the stent rods are arranged in a manner of being disposed between two adjacent leaflets.

4. The artificial valve prosthesis according to claim 3, wherein When the leaflet assembly is configured with multiple leaflets, the joint between two adjacent leaflets is configured as a second leaflet fixing portion, and the leaflet assembly is further fixed to the stent rod through the second leaflet fixing portion.

5. The artificial valve prosthesis according to claim 1, characterized in that, The stent rod is configured to have a first end for fixing to the first stent, and the stent rod further has a leaflet attachment portion for fixing the leaflet. The distance between the leaflet attachment portion and the end face of the first end accounts for 1 / 12 to 1 / 2 of the length of the stent rod.

6. The artificial valve prosthesis according to claim 1, characterized in that, The free end of at least one of the stent rods is configured as a hook portion for hooking the native leaflet or tissue.

7. The artificial valve prosthesis according to claim 6, characterized in that, At least two of the stent rods in the second stent are configured with the hook portion.

8. The artificial valve prosthesis according to claim 1, wherein, The leaflet cutting member is fixed to the connection end of the first stent and is located between two adjacent stent rods.

9. The artificial valve prosthesis according to claim 1, characterized in that, The included angle α is 0-45°.

10. The artificial valve prosthesis according to claim 1, characterized in that, The leaflet cutting member is configured with a plurality of cutting portions, and the cutting portions are configured as triangles, squares, or the cutting portions have arc-shaped cutting edges.

11. The artificial valve prosthesis according to claim 10, wherein, Along the extending direction of the leaflet cutting member, the plurality of cutting portions are arranged continuously, or the plurality of cutting portions are arranged discontinuously.

12. The artificial valve prosthesis according to claim 1, wherein, The stent body is configured as a non-closed structure, or the stent body is configured as a circumferentially closed annular structure.

Images